Motor control.



PATENTED OCT. 29. 1907.

E. R. GARIGHOPP.

MOTOR CONTROL. APPLICATION mun JAN. 26, 1004.

UNITED sTArns PATENT OFFICE.

EUGENE R. CARICHOFF, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO oT Is ELEVATOR COMPANY, OF EAST ORANGE, NEW JERSEY, A GORPORATIQN OF NEW JERSEY.

MOTOR. CONTROL.

Specifieation of Letters Patent.

Patented Oct. '29, 1907..

Application filed January 28. 1904 Serial No. 190.928.

ylen of the United States, residing in East Orange, Es

sex county, New J ersey,-.have invented certain new and useful Improvements in Motor Control, of whi ch the following is a specification.

My invention relates to a system for controlling electric motors and its object is to improve upon the systems now in use andto provide simple and efficient means for accomplishing this end. i

I will describe a motor control system embodying my invention and point out the novel features thereof in claims.

The drawing diagrammatically represents such a system.

designates a manually operated switch by means of which an operator controls the systemand the movements 0: the motor. 1.1, 12, 13, 14, 1'5 and 11 1.2, 13 l4, 15 are the stationary contacts of this handiswitch and 17 is its movable contact which is adapted to be moved over these stationarycontacts by means of a handle 16.

20 represents the armature of a motor, 21 its shunt field, 22 a brake magnet and 23, 24 its series fields.

A, B, C, D, E, F, G, H, l, I and K are magnetic switches adapted to open and close various circuits with the magnetic switches B and G and consists of two'- angular levers 41 and 42 pivoted at 43 and 44, engaging with the lower ends of the cores B and (J at 47 and 48 and with each other at 45 and 46. 30 is an automatic stop device. It consists of a cam 37 and two electrical switches with their connections.

Without further description of the drawing, I will proceed to trace out the various electrical circuits and describe the operation of the system. The mains which come from a suitable source of electrical supply are designated by and The positive main is connected to the movable contact 17 of the hand switch. When the movable contact 17 is moved to the right until it touches the stationary Contact 15 circuits are established through the solenoids A and G. The current will go through the car switch and to the contact 32 of the automatic stop device 30,'through the switch blade 35 and out through the contact '31. Thence it goes to the solenoid C where it branches. One part goes through the solenoid C and out to the'negative'main through the small contacts A and Aland the disk'A. Another part goes through the small contacts B and B and the disk B to the solenoidA, through thelatter and to the negative main through the contacts A and A The solenoids C and A will thus be energized and will draw up their cores C? and A C willbe drawn up to the position shown in the drawing and will be locked in that position by the lever 42, as the short arm 45 of lever 41 will come up behind the short arm 46 of lever 42 and as the lever 42 is connected at 48 to the core C it will hold the latter up in the position shown. This operation will cause the disk C to be raised from the small contacts Cand 0", and the disk (1 to be raised from the contacts 0' and C and against the contacts C and C At the same time-the core B (if it is not already down) will drop down into the position shown in the drawing because the short arm' 46 of the lever 42 will be removed from the back of the short arm 45. The disk- B will now rest upon the contacts B and B and the disk B rest upon the contacts B and B. It will be seen that unless the core B is down or until it has dropped down the circuit to the solenoid A is broken at B", B. When they are closed by the disk B the core A will be drawn up so that the disk A will connect the contacts'A A and A and the disk A will be raised from the contacts A and A The latter operation will break the circuit through the solenoid C so that no more current will pass through it while the core A remains up. But the core C will remain up as it is now locked in its up position by the arm 42 as we have already shown. The pin A will strike upon and raise the pivoted contact A from the contact A and this operation will insert the resistance A into the circuit of the solenoid A and so diminish the current used in A while its core A remains raised. Whenfithe disk A connects the contacts A A and A it closes a circuit through the brake magnet 22, one end of which is connected to the positive main and the other end of which is connected to the contact A and through the disk A to the negative main. This magnet is used in a well known way to release when it is excited a,brake from the moving part of the motor. The disk A also closes the circuit through the shunt field 21, one end of which is connected to the positive main and the other end of which is connected to the contact A, and through the disk A to the negative main. Another circuit is closed at the same time irom the positive main through the series fields 23 and 24 and the resistances I" H G F E and D the contacts C", and G which are connected by the disk 0 through the armature passing in at the brush 26 and leaving at the brush 25 through contacts 13 and B connected by the disk B, through A and A connected by the disk A to the negative main.- When the magnetic switches are in the position shown another circuit iscotnpletod throughthe armsmitted to tho armature through the series fields and resistance and that part of it is shunted around the armature througlr rtsistance. This will cause the armature to rotate slowly in one direction. As soon as it. rotate it generates a counter eloctro motive force and this will cause an increase of the current through the resistance 27 which causes the latter to act as a brake and prevent an undue acceleration of the armature.

If the movable contact 17 of the hand switch had beenmoved to the left onto contact 15' the operation would have been similar but in this case the disks of tho n-vorsirig switch I! would have been raised and those of the reversing switch would have been dropped, the current would have been sent through the armature in the opposite direction and the armature would have rotated in the opposite direction. If now tho movable contact 17 be inovod'iurther to the right. until .it touches the contact 14 a circuit will be closed through the solenoid I) of the. magnetic switch D. This 'cireuit \vill be completed from the positive maitrthrough the hand switch. the solenoid D, thence to tho small contact J through the disk I, contact J, and contact. A" which as we have already shown is now conncctod to the negative main. The current; flowing .through tho solenoid D will cause it to be energized and it will attract its core D'-' and draw it up. The disk l)=will be raised from the-contacts D=and D and against tho contacts D and D resistance I) will be added to the resistance 27 and at the same time tho resistance D which has been in series with the armature will be short-circuited. The. -efie(t of this upon the motor will be: first, to decrease the amountof currentwhich is shunted around the armature and decrease the reaking etl'ect;"t.hereof, and. second, to increase the current flowing through tho armature from the mains by decreasing the series resist-mice. Both of these actions will have the effect of increasing the rate of rotation of the armature. Similarly, when the movable contact 17' is. brought against contacts'13 and 12the solenoids E and F will be energized, the other cores E and F will be raised broken. When-the contacts G and Gare connected by the disk G, the resistance. G is short-circuited. Thus the effect of thisoperation of the magnetic switch (i will be similar to that of themagnetic switches D, E

In doing this themain line at A and A.

and F. Itwiltatso close the-circuit.through the solen" oids H. I,- J and K the effect of which will be presently described. This contact G is now connected through several disks and contacts and their connectionsto one of'tlmbrushes of the'armaturo.. It is also connectedto the upper side of the solenoids H, I, J and K; to H directly. to the others through resistances 1, J and K". The lower ends of the solenoids H, I, I and K are connected through various conductors and contacts to the other brush of the armature. Thus these four solenoids are connected in parallel across the brushes of the armature. As the latter a'ccelerates the counter electro-motive force will increase and the current passing through these solenoids will increase in proportion, to-theacceloration of the armature. The solenoid H is the only one of these four which is connected directly across the armature brushcs without the interposition of any external resistance. The solenoid I has a rtsistance I" connected in series with it. J has the resistance J in series with it and K has the resistance K in series with it. The resistance J is greater than the resistance 1 and the resistance K is greater than the resistance J 9. As the potential across the armature brushes increases these. solenoids will become more and more energized until they draw up their 1'( spective corcsl This they will do step by step beginning with H which has no rc-sistance in series with it, followed by-I, J and K bocause of the different amounts of resistance in series with each. When the core HE is drawn up, the disk H is brought against the contacts H and H and shortcircuits the rc'sistance H". This will tend to cause the armature to revolve faster. The core I with its disk I -will short-circuit the rcsistance I at the contacts I and I witlr'a similar result. When the, core J is pulled up, its disk J is raised from the small contacts J and J and is brought against the contacts J and J. This inserts the resistance]? in the circuit with the solenoids D. E. F and G which prevents them from using excessive current; and it short-circuits the series field 24. Similarly, when the core K is raised. the diskK? is lifted from the small contacts K and K and against the contacts K and K. This inserts the resistance K in the circuit with the solenoids H and I which prevents them from using excessive current, and it short-circuits the series field 23; The motor will now attain its full speed.

When it is desired to stop the motor automatically after it has run a predetermined number of revolution's.

as when it is directly connected to an electric elevator, the automatic stop device 30 may be used. In such a' case a cam 37 is so connected that it is moved by the retation of the armature until it either opens the switch blade 35 from its contacts 31 and 32 or the switch blade 36 from its contacts 33 and 34 according to the direction of the armatures rotation. This will break the circuit throughthe main line switch solenoid A and open the netic switches will be denergized. This will stop the motor as it will cut off its current supply and connect the resistance 27 across the brushes of its armature which will act, as a brake. It will be seen that only one side of the automatic stop device 30 will he opened at a time so that the operator may start the motor rotating in the opposite direction at will. This automatic stop de- All the solenoids of the magr 12. In motor-controlling apparatus, the combination with an electric motor, of armature-current reversing mechanism comprising two electric switches, electric means 7 for operating said reversing mechanillma main line switch, an auxiliary switch coacting with the main line switch to. cut oi! the current from sdid electric-operating-means,

- and.an interlocking .device for holding one of said iirstnamed electric switches in upper position and the other in lower position.

13. In motor-controlling apparatus, the. combination with an electric motor, of reversing switches therefor, electro-magnetstor operating said switches, a main line 1* In current-controlling apparatus, the combination with -current-reversing mechanism comprising two inde pendentiy operated switches, of electro-magnets tor changing the relative positions of said switches, and mechanical means for positively locking one switch in ciosed position until the other is moved a predetermined distance toward closed position. v

15. In current-controlling apparatus, the combination with two electro-magnetic switches for controlling the direction of current through a circuit, of a pivoted lever connected to a moving part or 'ea,ch'.ot said switches, and interlocking lugs on the inner ends of said levers and movable in arc, to mechanically lock one switch inciosed posi- I tion until theother is operated to a predetermined degree. In witness whereof, I have signed my name to this specification in the presence of two'suhscrihing witnesses. 4

EUGENE R. CARiCHOFF. Witnesses:

W. I]. Baanv, ERNEST W. Maasnann. 

